Acid milk beverages of a type containing living microbes such as fermented milk, lactic acid bacteria beverage and yogurt have been widely drunk as healthy beverages having physiological activities such as an effect of calming intestinal disorders and an immunopotentiating action. Further, since a culture liquid (a fermented milk base) prepared by incubation of lactic acid bacteria or microbes belonging to genus Bifidobacterium in a medium comprising a milk material has a specific taste, it has been utilized in various kinds of foods and beverages for the purpose of imparting flavor, etc. following a sterilizing treatment, etc.
Furthermore, in order to cope with the recent diversifying preferences of consumers, various types of acid milk beverages have been proposed in addition to the conventional acid milk beverages and, among them, development of an acid milk beverage of the so-called light type in which calorie is suppressed has been briskly carried out. Usually, such an acid milk beverage of a light type is produced in such a manner that, for suppressing the calories, glucides which are main calorie source are decreased or substituted with hardly-digesting glucides. However, dispersibility of milk protein usually becomes unstable under an acid condition and, therefore, there are problems that precipitation and aggregation upon storage, separation of whey, etc. are apt to occur when glucides are decreased or modified.
The above-mentioned precipitation, aggregation or whey separation not only deteriorate the appearance significantly but also affect the flavor upon drinking and further deteriorate the refreshing feel and, therefore, various methods have been proposed to improve these problems. To be more specific, there have been proposals for a method where a homogenizing treatment is applied with a purpose of improving the product quality stability of an acid milk beverage (Patent Document 1) and a method where one of thickening stabilizers such as pectin, carboxymethyl cellulose (CMC), soybean polysaccharide, gellan gum, locust bean gum, tamarind gum or propylene glycol alginate or two or more thereof is/are used together (Patent Documents 2 to 4).
As such, it is the current status that, in the production of acid milk beverage of a light type, various kinds of thickening stabilizers are commonly used.
Patent Document 1: JP-A-05-000043
Patent Document 2: JP-A-54-525754
Patent Document 3: JP-A-59-151837
Patent Document 4: JP-A-09-266779